DEHYDRIN PROFILES OF SOME IRANIAN MELON VARIETIES (Cucumis melo L. Merr) UNDER DROUGHT STRE SS CONDITIONS

Dehydrins are proteins that play a role in the mechanism of drought tolerance. This study aimed at establishing dehydrin profile and accumulation in four local melon varieties of Iran: Mino, Dargazi, Saveii, and Semsori, as well as in a commercial variety Honeydew. Plants were treated with drought stress by adjusting the soil water content to 75, 50, 40, 30 and 20% of field capacity (FC) by withholding water. Water status of plants was monitored based on the seedling fresh weight (FW) and relative water content of leaves (RWC). Total protein content was extracted, then heat-stable protein (HSP) fraction was isolated for each variety and water stress treatment. After SDS-PAGE of HSP, Western blotting analysis was carried out with Anti-dehydrin rabbit (primary) and Goat anti rabbit (secondary) antibodies. ANOVA results showed that with decreasing FC below 75%, FW and RWC decreased, but these changes significantly varied among genotypes. On the basis of FW and RWC data under different drought stress treatments, the following drought-tolerant ranking was established: Mino > Dargazi > Saveii and Honeydew > Semsori, from tolerant to sensitive order. Results of Western blot analysis showed that expression of some proteins with molecular weights of 19–52 kDa was induced in the studied varieties under drought stress (% FC). Expression level of the dehydrin proteins in different varieties was variable and also depending on the drought stress level applied. However, dehydrin proteins (45 and 50 kDa) showed strong expression levels in all varieties under severe drought stress (20% FC). The abundance of dehydrin proteins was higher in tolerant varieties (Mino and Dargazi) than in moderate and drought sensitive genotypes. Consequently, dehydrins represent a potential marker for selection of genotypes with enhanced drought tolerance.

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Evaluation of diverse cowpea [Vigna unguiculata (L.) Walp.] germplasm accessions for drought tolerance

Legume Research - An International Journal ◽

10.18805/lr-428 ◽

2019 ◽

Author(s):

K.D. Nkoana ◽

Abe Shegro Gerrano ◽

E.T. Gwata

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Water Content ◽

Relative Water Content ◽

Evaluation Method ◽

Moisture Stress ◽

Proline Content ◽

Drought Tolerant ◽

Relative Water ◽

Germplasm Accessions

The genetic potential for drought tolerance in cowpea within the small holder sector has not been fully exploited in South Africa. Thus, a drought evaluation experiment was conducted at the ARC-VOP to evaluate 28 cowpea germplasm accessions including two controls viz. IT96D-602 (drought tolerant) and TVU7778 (susceptible to drought) in the drought screening house using plastic box evaluation method in January, 2017. Genotypes raised for three weeks were subjected to 5 weeks of water stress treatment to determine their physiological response through leaf wilting index, relative water content and proline content followed by re-watering to determine genotype (s) with ability to recover from drought stress. Analyses of variance showed highly significant differences in response to moisture stress among the cowpea accessions for the selected physiological traits except for leaf wilting index at week two of drought stress. Stem greenness and recovery appeared to be a reliable indicator of drought tolerant genotypes which was readily observed in Acc1257, Acc1168, Acc2355, IT96D-602 and Acc5352 which also correlated significantly and positively with relative water content and proline content. The genotypes responded differently to drought stress indicating that there is sufficient genetic variability that can be utilized further in breeding for drought stress within the cowpea species.

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Leaf morphology, photochemistry and water status changes in resprouting Quercus ilex during drought

Functional Plant Biology ◽

10.1071/fp04137 ◽

2005 ◽

Vol 32 (2) ◽

pp. 117 ◽

Cited By ~ 41

Author(s):

Karen Peña-Rojas ◽

Xavier Aranda ◽

Richard Joffre ◽

Isabel Fleck

Keyword(s):

Drought Stress ◽

Quercus Ilex ◽

Structural Characteristics ◽

Water Status ◽

Stomatal Closure ◽

Severe Drought ◽

Clear Cut ◽

Leaf Mass Area ◽

Relative Water ◽

Moderate Drought

Functional and morphological (structural) characteristics of Quercus ilex L. leaves under drought stress were studied in the forest and in a nursery. We compared undisturbed individuals (controls) with resprouts emerging after clear-cut or excision. When soil water availability was high, gas-exchange was similar in resprouts and controls, despite higher midday leaf water potential, midday leaf hydration and relative water content (RWC). In moderate drought, stomatal closure was found to limit photosynthesis in controls, and in severe drought non-stomatal limitations of photosynthesis were also greater than in resprouts. Leaf structure and chemical composition changed under drought stress. Leaves tended to be smaller in controls with increasing drought, and resprouts had larger leaves and lower leaf mass area (LMA). The relationship between nitrogen (N) content and LMA implied lower N investment in photosynthetic components in controls, which could be responsible for their increased non-stomatal limitation of photosynthesis. Changes were more apparent in leaf density (D) and thickness (T), components of LMA. Decreases in D were related to reductions in cell wall components: hemicellulose, cellulose and lignin. In resprouts, reduced D and leaf T accounted for the higher mesophyll conductance (gmes) to CO2 measured.

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Seed Antioxidants Interplay with Drought Stress Tolerance Indices in Chilli (Capsicum annuum L) Seedlings

BioMed Research International ◽

10.1155/2018/1605096 ◽

2018 ◽

Vol 2018 ◽

pp. 1-14 ◽

Cited By ~ 7

Author(s):

U. Lakshmi Sahitya ◽

M. S. R. Krishna ◽

R. Sri Deepthi ◽

G. Shiva Prasad ◽

D. Peda Kasim

Keyword(s):

Water Stress ◽

Drought Tolerance ◽

Water Content ◽

Stress Tolerance ◽

Chlorophyll Content ◽

Relative Water Content ◽

Field Capacity ◽

Water Regimes ◽

Relative Water ◽

Tolerance Indices

Altering climatic conditions and water stress drastically affects the chilli crop yield. In this scenario we adapted a strategic approach for screening of elite chilli genotypes, by exploring role of seed antioxidants in stress tolerance during vegetative phase. A total of 20 chilli genotypes’ seed antioxidant potential and its effect on water stress tolerance were studied at three water regimes, namely, control (100% Field Capacity), moderate (80% Field Capacity), and severe (60% Field Capacity) stress conditions. Drought tolerance traits relative water content, chlorophyll content, and activities of superoxide dismutase and catalase enzymes were measured. A strong correlation was observed between seed antioxidants and water stress tolerant traits in seedlings. Genotypes KCa-5, KCa-6, and KCa-10 showed low quantity of H2O2 and Malondialdehyde in seeds and maintained high membrane integrity and chlorophyll content in seedlings. High content of proline in KCa-5, KCa-7, and KCa-10 seeds retained high relative water content at seedling stage under severe water stress. Present work reveals genotypic differences of hot pepper to different water regimes. Based on Principal Component Analysis (PCA) of seed antioxidant variables and drought tolerance indices twenty genotypes segregated into three clusters, namely, drought tolerant and susceptible and moderately tolerant.

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Potensi Abu Sekam Padi untuk Meningkatkan Ketahanan Oksidatif Non-enzimatik dan Produksi Padi Merah pada Cekaman Kekeringan

Jurnal Agronomi Indonesia (Indonesian Journal of Agronomy) ◽

10.24831/jai.v46i1.13205 ◽

2018 ◽

Vol 46 (1) ◽

pp. 24

Author(s):

Diah Rachmawati ◽

Ni Luh Gde Mona Monika ◽

Dan Ulfatul Masruroh

Keyword(s):

Drought Stress ◽

Water Content ◽

Relative Water Content ◽

Photosynthetic Apparatus ◽

Field Capacity ◽

Membrane Stability ◽

Severe Stress ◽

Enhanced Production ◽

Relative Water ◽

Leaf Relative Water Content

Drought inhibits several physiological process and induces oxidative stress due to the enhanced production of reactive oxygen species (ROS) mainly in photosynthetic apparatus. Silicon (Si) is known to increase tolerance of rice against drought stress. However, long period of intensive crop cultivation depleted the available soil Si by approximately 11-20%. Rice husk ash (RHA) is potential Si source. The objective of this research was to analyze the potency of RHA through pot experiment to observe: 1) internal water balanced; 2) integrity of cell membrane and antioxidant content; and 3) production of tolerant cultivar ‘Segreng’ and sensitive one ‘Cempo merah’. Application of RHA was at level of 0, 4, and 8 tons ha-1. Drought stress was imposed by with holding water until soil water content reached 50% of field capacity (moderate stress) and 25% of field capacity (severe stress). Application of RHA significantly increased leaf relative water content and membrane stability index of rice ‘Segreng’ and ‘Cempo merah’. Tolerant cultivar ‘Segreng’ had better response than ‘Cempo merah’ as shown by greater leaf relative water content under moderate and severe stress. RHA application at level of 8 tons ha-1 increased index of membrane stability and level of antioxidant (AAred and α-tocopherol) which determine production of both rice ‘Segreng’ and ‘Cempo merah’ during drought. Keywords: antioxidant, field capacity, membrane stability, segreng cultivar, α-tocopherol

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(452) Growth Responses of Salvia greggii and Dalea frutescens to Drought Stress

HortScience ◽

10.21273/hortsci.40.4.1036a ◽

2005 ◽

Vol 40 (4) ◽

pp. 1036A-1036

Author(s):

Genhua Niu ◽

Denise S. Rodriguez

Keyword(s):

Water Stress ◽

Drought Stress ◽

Drought Tolerance ◽

Water Potential ◽

Water Content ◽

Water Status ◽

Irrigation Management ◽

Growth Responses ◽

Shoot Number ◽

Dry Down

Salvia greggii (salvia) and Dalea frutescens (dalea) are two popular shrubs. However, little information is available on their drought tolerance. The objectives of this study were to investigate the effect of various degrees of water stress on growth and to characterize the dynamics of water relations to root substrate water content for developing best irrigation management. Salvia and dalea plants in 12-L plastic containers were grown in a greenhouse and pruned to one node at the base of the soft shoots for salvia or at the same height for dalea prior to the start of the experiment. There were three irrigation regimens: plants were irrigated daily (control), or irrigation was withheld until moderate or severe water stress signs exhibited. After several weeks of intermittent cyclic dry-down irrigation regimens, total shoot number per container was reduced by 40% to 50% for salvia and 35% to 40% for dalea. Average shoot length was reduced by 35% to 45% for salvia and 50% to 65% for dalea in moderate and severe stressed treatments compared to the control. Drought stress resulted in less shoot elongation and fewer new shoots in both species. To examine the relationship between plant water status and substrate water content, a dry down test was performed on five well-watered plants by withholding irrigation until midday water potential dropped to below –4 MPa. As substrate water contents in both species reached 8%, the predawn water potentials did not recover from the midday water potential of the previous day, indicating there was no available water in the substrate for roots to take up. The drought tolerance of these two species needs further study using various growing media.

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Study some of Morphological and Physiological Traits of Kurrajong Brachychiton populneus (Schott & Endl.) Seedlings Planted under Water Stress Conditions

Basrah Journal of Agricultural Sciences ◽

10.37077/25200860.2020.33.1.16 ◽

2020 ◽

Vol 33 (1) ◽

pp. 213-220

Author(s):

Shaima A. Karim ◽

Sirwa A. Qadir ◽

Halmat A. Sabr

Keyword(s):

Drought Stress ◽

Water Content ◽

Chlorophyll A ◽

Relative Water Content ◽

Photosynthetic Pigment ◽

Total Content ◽

Dry Weight ◽

Severe Drought ◽

Shoot Height ◽

Relative Water

In this study, Brachychiton populneus seedlings were subjected to drought stress for 90 Days and physiological and morphological characters analyzed to determine their response to water deficit. The growth characters including, height and diameter of shoots, the dry weight of shoots and roots as well as photosynthetic pigment and the leaves content of relative water content were measured to evaluate the effects of drought in the physiological growth of plant. The lowest means; 59 cm and 8 mm of shoot height and diameter respectively were recorded at 30% of water holding capacity of soil (WHC). Drought treated seedlings at both 60% and 30% WHC had lower dry weight of shoots; 9.54 and 8.24 g plant-1 respectively compared to the control. Consequently, the increase of drought conditions led to enhancement the growth of roots and roots to shoots ratio. The highest increase in the dry weight of roots and roots to shoots ratio were25.96 g plant-1 and 3.19 recorded under severe drought stress condition. Lowest amount of chlorophyll a; 2.94 mg g-1 F W recorded under 30% SWHC. It is found also the total content of chlorophyll in the leaves decreased significantly; 5.86 and 7.88 mg g-1 F W under both levels. While the highest ratio of chlorophyll a: b was 1.59 recorded at 60% SWHC. However, the lowest leave relative water content LRWC%; 86% was recorded under 30% SWHC. These findings may explain the characters of the early growth and physiological responses of, Brachychiton populneus to dehydration and facilitate the selection of drought-resistant tree families.

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Development of a diurnal dehydration index for spring barley phenotyping

Functional Plant Biology ◽

10.1071/fp14069 ◽

2014 ◽

Vol 41 (12) ◽

pp. 1249 ◽

Cited By ~ 10

Author(s):

Pablo Rischbeck ◽

Peter Baresel ◽

Salah Elsayed ◽

Bodo Mistele ◽

Urs Schmidhalter

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Water Content ◽

Water Status ◽

Spring Barley ◽

Leaf Water ◽

Leaf Angle ◽

Leaf Water Content ◽

Diurnal Changes ◽

Angle Distribution

Spectral and thermal assessments may enable the precise, high-throughput and low-cost characterisation of traits linked to drought tolerance. However, spectral and thermal measurements of the canopy water status are influenced by the crops’ soil coverage, the size of the biomass and other properties such as the leaf angle distribution. The aim of this study was to develop a referenced spectral method that would be minimally influenced by potentially perturbing factors for retrieving the water status of differing cultivars. Sixteen spring barley cultivars were grown in field trials under imposed drought stress, natural drought stress and irrigated conditions. The relative leaf water content of barley plants declines diurnally from pre-dawn until the afternoon, and other plant traits such as the biomass change little throughout the day. As an indicator of the current drought stress, pre-dawn and afternoon values of the relative leaf water content were assessed spectrally. Diurnal changes in reflectance are only slightly influenced by other perturbing factors. A new spectral index (diurnal dehydration index) was developed by using the wavelengths 730 and 457 nm collected from an active spectrometer. This index allowed the differentiation of the drought tolerance of barley plants. The diurnal dehydration index was significantly related to final biomass, grain yield and harvest index and significantly different between cultivars. Compared with other indices, the diurnal dehydration index offered a higher stability in retrieving the water status of barley plants. Due to its diurnal assessment, the index was barely influenced by the differences in cultivars biomass at the time of measurement. It may represent a valuable tool for assessing the water status or drought tolerance in breeding nurseries.

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Physiological responses of mungbean (Vigna radiata) varieties to drought stress

Bangladesh Journal of Agricultural Research ◽

10.3329/bjar.v44i1.40899 ◽

2019 ◽

Vol 44 (1) ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

A Nazran ◽

JU Ahmed ◽

AJMS Karim ◽

TK Ghosh

Keyword(s):

Drought Stress ◽

Physiological Responses ◽

Field Capacity ◽

Water Relation ◽

Severe Drought ◽

Water Regimes ◽

Randomized Design ◽

Physiological Adaptations ◽

Relative Water ◽

Moderate Drought

A pot experiment under polyshed condition was carried out at Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur during the period from 27 March 2017 to 5 May 2017 to study the physiological responses of mungbean varieties to drought stress under varying water regimes. The treatments consisted of four mungbean varieties, namely BARI Mung-5, BARI Mung-6, BUmug 2, BUmug 4 and three water regimes viz., 50 to 60% field capacity (FC), 70 to 80% FC and 90 to100% FC which were considered as severe drought stress, moderate drought stress and non-stress, respectively. The experiment was laid out in a completely randomized design with factorial arrangement having four replications. Results indicated that BARI Mung-6 maintained significantly the highest relative water content, leaf water potential, proline content, shoot dry matter and lower rate of electrolyte leakage at 50 to 60% FC (severe drought stress). BUmug 2 showed the lowest performance in terms of all the water relation and physiological characters which indicates its higher sensitivity to severe drought stress. Variety BARI Mung-6 was relatively water stress tolerant than others in respect of physiological adaptations. So, BARI Mung-6 can be a potential variety for cultivation under drought condition where irrigation facility is limited. Bangladesh J. Agril. Res. 44(1): 1-11, March 2019

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MORPHO-PHYSIOLOGICAL AND BIOCHEMICAL TRAIT BASED SELECTION OF WHEAT GENOTYPES FOR DROUGHT TOLERANCE

Bangladesh Journal of Plant Breeding and Genetics ◽

10.3329/bjpbg.v28i2.29961 ◽

2015 ◽

Vol 28 (2) ◽

pp. 09-16

Author(s):

S. A. Raffi ◽

M. Asaduzzaman

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Wheat Variety ◽

Field Capacity ◽

Tolerance Index ◽

Wheat Genotypes ◽

Leaf Chlorophyll ◽

Relative Water ◽

Major Bottleneck ◽

Physiological And Biochemical

Drought stress is now become the most important abiotic stress for wheat in Bangladesh. Rabi season often compromised wheat production by imposing drought stress. Therefore, it has been a priority to develop drought tolerant wheat variety for Bangladesh. However, the lack of genetic variability for drought tolerance in wheat has been a major bottleneck for developing drought tolerance wheat variety. The present investigation was carried out in an aim to evaluate several exotic and locally cultivated wheat genotypes for drought tolerance based on morpho-physiological and biochemical traits. Experiment was carried out at the net house of Field Laboratory of Department of Genetics and Plant Breeding, Bangladesh Agricultural University, Mymensingh with seven replications in a RCBD design. Ten locally cultivated and exotic wheat genotypes were grown under control (100% field capacity) and drought (30% field capacity) conditions. Genotypes used in the study were identified with different types of drought tolerance mechanisms, viz., Berkut for earliness, Shatabdi for grain weight, BARI Gom 26 for spike and grain number, along with Vorobey, Berkut for enhanced biosynthesis of proline, Sokoll for undamaged leaf Chlorophyll content and relative water content, Sakha8, Gaurav, Sonalika and Shatabdi for membrane thermostability; Sakha8 and Sourav for improved stress tolerance index. The genotypes screened out with different traits related to drought tolerance can be utilized as gene source for future breeding programs.

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The Method of Plant Water Status Measurement in Sweet Potato (Ipomoea Batatas (L) Lam.)

Beccariana Botanical Research Bulletin ◽

10.30862/bbrp.v7i1.274 ◽

2010 ◽

Vol 7 (1) ◽

Author(s):

Saraswati Prabawardani

Keyword(s):

Water Content ◽

Sweet Potato ◽

Relative Water Content ◽

Water Status ◽

Plant Water Status ◽

Equilibration Time ◽

Plant Water ◽

Font Size ◽

Potato Leaf ◽

Relative Water

The measurement of plant water status such as leaf water potential (LWP) and leaf relative water content (RWC) is important part of understanding plant physiology and biomass production. Preliminary study was made to determine the optimum amount of leaf abrasion and equilibration time of sweet potato leaf inside the thermocouple psychrometer chambers. Based on the trial, the standard equilibration time curve of a Peltier thermocouple for sweet potato leaf was between 2 and 3 hours. To increase the water vapour conductance across the leaf epidermis the waxy leaf cuticle should be removed or broken by abrasion. The result showed that 4 times leaf rubbings was accepted as the most effective way to increase leaf vapour conductance of sweet potato in the psychrometer chambers. In calculating the leaf relative water content, unstressed water of sweet potato leaves require 4 hours imbibition, whereas water stressed of sweet potato leaves require 5 to 6 hours to reach the saturation time. Either leaf water potential or relative water content can be used as a parameter for plant water status in sweet potato.

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